CVE-2026-18938

MEDIUMPre-NVD 6.26.2—
EchelonGraph scoreMEDIUM confidence

Score 6.2 from GitHub Security Advisory published 2026-08-07. a secondary CVSS source baseline 6.2; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
6.2EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.2Exploit: None knownExposed: 0

A fix is available — apply it.

A flaw was found in p11-kit. A local attacker, or one with equivalent access to a reachable RPC channel, could exploit an integer overflow vulnerability. By sending specially crafted messages, the attacker can cause the system to miscalculate memory allocation for nested attributes. This leads to a memory corruption issue, specifically a heap out-of-bounds write, which can crash the p11-kit RPC parsing process, resulting in a Denial of Service (DoS). This vulnerability is only exploitable on 32 bit systems.

CVSS v3
6.2
EG Score
6.2(medium)
EG Risk
28(Track)
EG Risk 28/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity62% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
1%
KEV
Not listed

Published

August 7, 2026

Last Modified

August 14, 2026

Advisory Details (2)

Auto-updated Aug 7, 2026
Patch available. Sources: redhat.
redhat

2478995 – (CVE-2026-18938) CVE-2026-18938 p11-kit: Integer overflow in RPC attribute-array length calculation can under-allocate nested attribute storage on 32 bit systems

https://bugzilla.redhat.com/show_bug.cgi?id=2478995
redhat Patch Available

CVE-2026-18938 - Red Hat Customer Portal

Affected: Red Hat Enterprise Linux 8 or OpenShift Container Platform 4, is affected by this vulnerability and a fix may be released to a

https://access.redhat.com/security/cve/CVE-2026-18938

Vendor Advisories for CVE-2026-18938(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntup11-kit-modules (0.23.9-2ubuntu0.1+esm1) @ bionic2026-09-20ubuntu

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
p11-kit0.23.22-1 ... 0.26.4-1 (33 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
p11-kit0.24.1-2 ... 0.26.5-1 (25 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
p11-kit0.25.10-1 ... 0.26.5-1 (9 versions)——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
p11-kit0.25.10-1 ... 0.26.4-1 (8 versions)0.26.5-1—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 19× in last 7d / 89× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 134 total refreshes for this CVE.

  1. 2026-09-20 20:33 UTCEG score recompute
  2. 2026-09-20 20:33 UTCVendor advisory
  3. 2026-09-20 20:33 UTCGHSA enrichment
  4. 2026-09-19 12:58 UTCEG score recompute
  5. 2026-09-19 12:58 UTCVendor advisory
  6. 2026-09-19 12:58 UTCGHSA enrichment
  7. 2026-09-18 19:27 UTCEPSS rescore
  8. 2026-09-18 07:25 UTCEG score recompute
  9. 2026-09-18 07:25 UTCVendor advisory
  10. 2026-09-18 07:25 UTCGHSA enrichment
  11. 2026-09-17 05:17 UTCEG score recompute
  12. 2026-09-17 05:17 UTCVendor advisory
  13. 2026-09-17 05:17 UTCGHSA enrichment
  14. 2026-09-16 14:07 UTCEPSS rescore
  15. 2026-09-16 03:09 UTCEG score recompute
  16. 2026-09-16 03:09 UTCVendor advisory
  17. 2026-09-16 03:09 UTCGHSA enrichment
  18. 2026-09-15 01:01 UTCVendor advisory
  19. 2026-09-15 01:01 UTCGHSA enrichment
  20. 2026-09-13 18:43 UTCEG score recompute
  21. 2026-09-13 18:43 UTCVendor advisory
  22. 2026-09-13 18:43 UTCGHSA enrichment
  23. 2026-09-13 16:46 UTCEPSS rescore
  24. 2026-09-12 16:35 UTCEG score recompute
  25. 2026-09-12 16:35 UTCVendor advisory
Show 75 more
  1. 2026-09-12 16:35 UTCGHSA enrichment
  2. 2026-09-12 15:00 UTCEPSS rescore
  3. 2026-09-11 14:52 UTCEPSS rescore
  4. 2026-09-11 14:27 UTCEG score recompute
  5. 2026-09-11 14:27 UTCVendor advisory
  6. 2026-09-11 14:27 UTCGHSA enrichment
  7. 2026-09-11 09:36 UTCEPSS rescore
  8. 2026-09-10 09:34 UTCEPSS rescore
  9. 2026-09-10 08:09 UTCVendor advisory
  10. 2026-09-10 08:09 UTCGHSA enrichment
  11. 2026-09-09 06:01 UTCEG score recompute
  12. 2026-09-09 06:01 UTCVendor advisory
  13. 2026-09-09 06:01 UTCGHSA enrichment
  14. 2026-09-08 22:00 UTCEPSS rescore
  15. 2026-09-07 17:46 UTCEG score recompute
  16. 2026-09-07 17:46 UTCVendor advisory
  17. 2026-09-07 17:46 UTCGHSA enrichment
  18. 2026-09-06 13:47 UTCEPSS rescore
  19. 2026-09-06 13:23 UTCEG score recompute
  20. 2026-09-06 13:23 UTCVendor advisory
  21. 2026-09-06 13:23 UTCGHSA enrichment
  22. 2026-09-05 11:15 UTCEG score recompute
  23. 2026-09-05 11:15 UTCVendor advisory
  24. 2026-09-05 11:15 UTCGHSA enrichment
  25. 2026-09-04 09:07 UTCEG score recompute
  26. 2026-09-04 09:07 UTCVendor advisory
  27. 2026-09-04 09:07 UTCGHSA enrichment
  28. 2026-09-04 05:06 UTCEPSS rescore
  29. 2026-09-03 06:08 UTCEG score recompute
  30. 2026-09-03 06:08 UTCVendor advisory
  31. 2026-09-03 06:08 UTCGHSA enrichment
  32. 2026-09-02 14:11 UTCEPSS rescore
  33. 2026-09-02 00:48 UTCEG score recompute
  34. 2026-09-02 00:48 UTCVendor advisory
  35. 2026-09-02 00:47 UTCGHSA enrichment
  36. 2026-09-01 13:53 UTCEPSS rescore
  37. 2026-08-31 22:30 UTCEG score recompute
  38. 2026-08-31 22:30 UTCVendor advisory
  39. 2026-08-31 22:30 UTCGHSA enrichment
  40. 2026-08-30 19:17 UTCEPSS rescore
  41. 2026-08-30 12:43 UTCEG score recompute
  42. 2026-08-30 12:43 UTCVendor advisory
  43. 2026-08-30 12:43 UTCGHSA enrichment
  44. 2026-08-30 01:22 UTCEPSS rescore
  45. 2026-08-29 10:25 UTCEG score recompute
  46. 2026-08-29 10:25 UTCVendor advisory
  47. 2026-08-29 10:25 UTCGHSA enrichment
  48. 2026-08-28 21:41 UTCEPSS rescore
  49. 2026-08-27 21:41 UTCEG score recompute
  50. 2026-08-27 21:41 UTCGHSA enrichment
  51. 2026-08-27 14:25 UTCEPSS rescore
  52. 2026-08-26 19:34 UTCEG score recompute
  53. 2026-08-26 19:33 UTCGHSA enrichment
  54. 2026-08-26 14:46 UTCEPSS rescore
  55. 2026-08-25 17:18 UTCEG score recompute
  56. 2026-08-25 17:18 UTCGHSA enrichment
  57. 2026-08-25 13:48 UTCEPSS rescore
  58. 2026-08-24 14:32 UTCEG score recompute
  59. 2026-08-24 14:32 UTCGHSA enrichment
  60. 2026-08-23 12:25 UTCEG score recompute
  61. 2026-08-23 12:25 UTCGHSA enrichment
  62. 2026-08-23 00:19 UTCEPSS rescore
  63. 2026-08-22 10:17 UTCEG score recompute
  64. 2026-08-22 10:17 UTCGHSA enrichment
  65. 2026-08-21 23:49 UTCEPSS rescore
  66. 2026-08-21 08:08 UTCEG score recompute
  67. 2026-08-21 08:08 UTCGHSA enrichment
  68. 2026-08-20 22:55 UTCEPSS rescore
  69. 2026-08-20 06:00 UTCEG score recompute
  70. 2026-08-20 06:00 UTCGHSA enrichment
  71. 2026-08-19 17:03 UTCEPSS rescore
  72. 2026-08-19 03:52 UTCEG score recompute
  73. 2026-08-19 03:52 UTCGHSA enrichment
  74. 2026-08-18 13:48 UTCEPSS rescore
  75. 2026-08-18 01:44 UTCEG score recompute

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ubuntu:USN-8687-1

Frequently asked(5)

What is CVE-2026-18938?
CVE-2026-18938 is a medium vulnerability published on August 7, 2026. A flaw was found in p11-kit. A local attacker, or one with equivalent access to a reachable RPC channel, could exploit an integer overflow vulnerability. By sending specially crafted messages, the attacker can cause the system to miscalculate memory allocation for nested attributes. This leads to a…
When was CVE-2026-18938 disclosed?
CVE-2026-18938 was first published in the National Vulnerability Database on August 7, 2026, with the most recent update on August 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-18938 actively exploited?
CVE-2026-18938 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 98.7% of all scored CVEs.
What is the CVSS score of CVE-2026-18938?
CVE-2026-18938 has a CVSS v3 base score of 6.2 (NVD).
How do I remediate CVE-2026-18938?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-18938, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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